Various processes have been developed to apply coatings to glass containers for different purposes, including glass strengthening for damage prevention and fragment retention. For example, U.S. Pat. No. 3,522,075 discloses a process for coating a glass container in which the glass container is formed, coated with a layer of metal oxide such as tin oxide, cooled through a lehr, and then coated with an organopolysiloxane resin-based material over the metal oxide layer. In another example, U.S. Pat. No. 3,853,673 discloses a method of strengthening a glass article by, for example, applying to a surface of the article a clear solution of a soluble, further hydrolyzable metallosiloxane, and maintaining the glass article at an elevated temperature sufficiently high to convert the metallosiloxane to a heat-treated polymetallosiloxane gel structure. In a further example, U.S. Pat. No. 3,912,100 discloses a method of making a glass container by heating the glass container and applying a polyurethane powder spray to the glass container.
A general object of the present disclosure is to provide an improved method of applying, to a glass container, a coating that reduces light reflectivity.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A method of applying an inorganic-organic hybrid coating having anti-reflective properties to a glass container may include the step of (a) applying a coating composition over an exterior surface of a glass substrate that defines a shape of the glass container. The coating composition applied in step (a) may comprise (1) a UV curable organofunctional silane that includes an alkoxy functional group and an acrylic ester functional group, (2) colloidal silica, (3) water, (4) a catalyst, and (5) an organic solvent. The method may further include the step of (b) exposing the coating composition to UV light for a time sufficient to cure the coating composition into a transparent monolithic inorganic-organic hybrid coating that comprises an inorganic polymer component and an organic polymer component. The inorganic-organic hybrid coating may provide an optical transmission gain relative to the glass substrate of at least 1% for light at a wavelength of 555 nm.
In accordance with another aspect of the disclosure, there is provided a method of applying an inorganic-organic hybrid coating having anti-reflective properties to a glass container. The method may include the steps of (a) providing a glass container that includes a soda-lime glass substrate that defines a shape of the container; (b) applying a coating composition over an exterior surface of the glass substrate; and (c) exposing the coating composition to UV light for a time sufficient to cure the coating composition into a monolithic inorganic-organic hybrid coating. The coating composition applied in step (b) may comprise (1) a UV curable organofunctional silane that includes an alkoxy functional group and an acrylic ester functional group, (2) colloidal silica, (3) water, (4) a catalyst, and (5) an organic solvent. A photoinitiator and a non-silane monomer or polymer that includes an acryl functional group or an epoxide functional group may be excluded from the coating composition.
In accordance with an additional aspect of the disclosure, there is provided a glass container that may include an axially closed base at an axial end of the glass container, a body extending axially from the base and being circumferentially closed, and an axially open mouth at another end of the glass container opposite of the base. The glass container may also include an inorganic-organic hybrid coating over an exterior surface of the glass substrate. The inorganic-organic hybrid coating may comprise an inorganic polysiloxane polymer component and an organic polyacrylic polymer component, and may further provide an optical transmission gain of at least 1% relative to the glass substrate for light at a wavelength of 555 nm.